Machine for grinding screw-cutting dies or chasers.



Np. 791,201. PATENTED MAY 30, 1905.

E. J; MILLER. MACHINE FQR GRINDING SGREW CUTTING DIES 0R GHASERS.

APPLICATION FILED JAN. 26. 1905.

3 SHEETSSHEBT 1.

PATENTBD'MAY 30, 1905.

E. J. MILLER. MACHINE FOR GRINDING SCREW CUTTING DIES 0R GHASERSAPPLIOATION FILED JAN. 26, 1905.

3 SHEETS-SHEET 2.

w k k-N @WW 1). mfriwinnl w a L-\ l i5 any lvvlllllldrllll/d/llw AWQ 0 4l PATENTED MAY 30, 1905.

u v J.IMILLE R. MACHINE POR'GRINDING SCREW CUTTING DIES OR OHASER'S.

' APPLICATION TILED JAN. 26. 1905 3 SHEETS-SHEET 3.

UNITED STATES IPatented. May 30, 1905.

PATENT OFFICE.

EDWARD J; MILLER, OF ST. LOUIS, MISSOURI, ASSIGNOR TO ST. LOUIS SCREWCOMPANY, ST. LOUIS, MISSOURI, A CORPORATION.

MACHINE FOFI' GRINDING SCREW-CUTTING DIES OR CHASERS.

\ SPECIFICATION forming part of Letters Patent No. 791,201, dated May30, 1905.

I Application filed Ianuary 26, 1905. Serial No. 242,745.

' To all, whom it may concern.-

Be it known that I, EDWARD J. MILLER, a

citizen of the United States, residing in the is a full, clear, andexact description, reference being had to the accompanying drawings,forming part of this specification.

My invention relates to a machine for grinding screw-cutting dies orchasers, such as are used in bolt or pipe cutting machines, and dieheadsin which the cutters are removable from their holders. In grinding diesor chasers of this type the essential features are, first, that they beground in such manner that the cutting edges of the throats will not beweakened and that the die or chaser will not ride upon the throat,thereby causing chattering of the die or chaser; second, that the diesorchasers be so ground at the proper angle to suit the class of work theyare to perform; third, that they be ground alike, so that all the diesor chasers mounted in a holder will do their proper proportion of work.In most instances this grinding has been accomplished by hand, and it ispractically impossible to carry out the essential characteristic ofgrinding when work is so done. accomplishing this work, so far as I amaware, use has been made of very small emery-wheels for grinding actionconforming to the size of the Work the dies or chasers are to operateupon in order to obtain proper curvature and clearance in the throats ofthe dies or chasers. In this practice the grinding-wheel beingnecessarily small to conform to the die or chaser it has been found nextto impossible to run it at a speed high enough to secure free cutting orgrinding of the die or chaser throat, owing to the peripheral surfacebeing so small that it will not retain its size, and consequently itfails to grind the set of dies or chasers correspondingly due to wear.In addition the grinding-wheel spindle is necessarily small tocorrespond to the size of the wheel, and in consequence of its beingnecessary to locate the grinding-wheel upon said spindle beyond the Inprevious machines for.v

spindle-bearing as it stands in the grindingline the spindle is so frailthat it is subject to springing action, and therefore the grindingaction is inaccurate.

In my machine all of the objectionable features pointed out areobviated, as by the peculiar arrangement of the parts of the machine Iam enabled to use a grinding-wheel of prac-- tically any diameter, dueto the parts being so arranged that the proper curvature of the die orchaser throat is secured in grinding action by swinging the die-holderand its carrying member to the proper angle so that the die or chaserwill be caused to travel across the periphery of the grinding-wheel inan oblique direction, the degree of obliquity corresponding to theparticular curvature of the die or chaser throat. In this connection itmay be stated that the peripheral face of the grinding-wheel should bekept narrow, so that if the die or chaser to be ground thereby weremoved vertically it would be ground of a shape corresponding to theperipheral face of the grinding-wheel; but by throwingthe die-holderinto an inclined position the ground throat of the die or chaser Willassume a curve, becoming larger with increased angle until when thedie-holder is horizontal the curvature with which the throat is groundwould be the same as the peripheral curvature of the grinding-Wheel. Inmy machine pro: vision is made for advancing the die-holder to thegrinding-wheel for grinding action in line of the grinding-Wheel spindlefor clearance of the cutting edge and also for holding the dies orchasers by either front or rear sides in order to provide for the propergrinding of the dies or chasers, which in some dieheads are alined bytheir front faces and in some by their rear faces. For the purpose ofinsuring that all ,dies or chasers be ground alike, even if of unequallength, I provide a gage which is adapted to beadjusted to the teeth ofthe die or chaser when clamping it in the holder to be ground. This gageis preferably of such configuration at its dieengaging portion that itwill extend across several of the teeth of the die or chaser, and itsteeth-engaging portion is made of a shape to conform to the generaltrend of the teeth Whether such trend be tapering or in straighttransverse line.

Figure I is a front elevation of my machine, in which only the upperportion of the stand is illustrated. Fig. II is a side elevation of theparts shown in Fig. I. Fig. III is a vertical section taken on line IIIIII, Fig. I. Fig. IV is a vertical section taken on line IV IV, Fig.III. Fig. IV is a view showing in detail the outer end of the bed-plateand parts associated therewith. Fig. V is a cross-section taken on lineV V, Fig. III. Fig. VI is an enlarged view taken partly in section online VI VI, Fig. III, and showing portions beneath said line in plan.Fig. VII is an enlarged cross-section taken through the dieholder. Fig.VIII is a vertical section taken on line VIII VIII, Fig. VII, throughthe dieholder. Fig. IX is a top view of a portion of thedie-holder-carrying slide, showing the curved runway therein in whichthe gageearrying rod operates. Fig. X is an enlarged section taken online X X, Fig. II, through a portion of the die-holder. Fig. XI is afront view of one of the dies or chasers such as are ground in mymachine. Fig. XII is an end view of the die or chaser shown in Fig. XI.Fig. XIII is an edge view of the toothed end of a die or chaser, showingthe cutting-throat.

1 designates the post of the stand of my machine, the upper end of whichis bifurcated to provide arms 2, supporting journal-boxes 3, in which isfitted a spindle 4, that carries a grinding-wheel 5.

6 is an arm extending laterally from the stand-post 1 and terminating ina table 7. (See Figs. I, III, and IV.)

8 is a bed-plate that is reciprocally mounted upon the table 7 formovement toward and away from the periphery of the grindingwheel 5.Reciprocation is imparted to the bed-plate 8 through the medium of ashiftscrew 9, that operates in a screw-threaded bore in the table 7 andextends longitudinally beneath said bed-plate and through a bearingmember 10, that is fitted to the outer end of said plate, as shown mostclearly in Fig. IV. Fixed to the shift-screw 9, at the inner side of thebearing member 10, is a collar 11, that bears against said member, andfixed to the shift-screw at the other side of the bearing member is agage or scale disk 12, that is adapted to rotate with the shiftscrew toserve as an indicator of the adjustment of said screw through the mediumof the scale thereon registering with a mark upon the bearing member 10,as seen in Fig. IV. By this means the degree of adjustment of thebedplate 8 to and from the periphery of the grinding-wheel 5 may beaccurately determined.

13 designates a carriage-bed reciprocally mounted upon the bed-plate 8and adapted for movement transversely of said bed-plate and alsotransversely of the grinding-wheel 5. This bed is provided at its outerside with an upright wing 14, and it is shifted through the medium of ashift-screw 15, that is seated in a screw-threaded bore in the bed-plate8 (see Fig. III) and has fixed thereto a pair of collars 16, thatoperate in engagement with a bearing member 17, fixed to the outer endof the carriage-bed.

18 designates an oscillating plate that is provided with an car 19,which is swiugingly connected to the wing 14 of the carriage-bed 13 bymeans of a stub-shaft 20. fixed to the car '19 (see Fig. V) andextending through the wing 14, this stub-shaft being equipped with aclamp-nut 21, by which the oscillatingplate car may be drawn tightly tothe wing 14 to hold the oscillating plate from movement. The oscillatingplate is thereby so supported that it may be oscillated transversely ofthe grinding-wheel 5 to place the plate at any desired inclination to ahorizontal or perpendicular line. For the purpose of determining thedegree of inclination of the oscillating plate I provide the carriagebedwing 14 with ascale and also providean indicating-mark upon theoscillating-plate car.

22 designates a slide reciprocally mounted upon the oscillating plate 18and arranged for movement on said plate in a direction transversely ofthe grinding-wheel 5 or in a direction obliquely to the axis of saidgrindingwheel. The slide 22 is reciprocated through the medium of ahand-lever 23, that is fulcrumed at 24 in a pivot-stem 25, projectingfrom the oscillating-plate car 19, and has connected to -it a link 26,that is pivotally united at 27 to the slide 22.

28 is a protective casing secured to the oscillating plate 18 at itsrear end and into which the slide 22 operates.

29 designates a die-holder that is rotatably mounted upon the slide 22,to which it is held by a swivel-bolt 30. (See Figs. I, II, III], andVII.) The die-holder is provided with a pocket for the reception of thedie or chaser to be ground and which protrudes from said pocket in adirection toward the grinding-wheel 5, as seen in Fig. I. It isessential in grinding dies or chasers that such tools he held in a dieholder by pressure of the retaining device either against the side orback of the tool, according to whether the tool is alined by its frontface or by its rear face. For this reason I provide a clamping memberfor engag(. ment with the front face of the die or chaser and also aclamping member for engagement with the rear face of the die or chaser,either of which is to be used independently of the other.

31 designates a clamping-screw that extends downwardly through thedie-holder at the location of the pocket therein and which is adapted toengage the front of the die or chaser seated in the die-receivingpocket.

IIC

82 is a clamping-bolt that is movably positioned in the die-holder 29and equipped at its upper or outer end with a nut 33, by which it may bemoved upwardly and downwardly. The clamping-bolt is provided at itslower end with a laterally-extending arm 34, that extends beneath thedie-holder pocket and terminates in a stud 35, which enters into thedie-holder pocket. This stud is adapted to bear against the rear of thedie or chaser in said pocket and clamp the tool therein by pressing itupwardly against the top wall of the pocket when the nut 33 of theclamp-bolt is drawn tight.

36 designates a gage-arm, the free end of which is provided with aknife-edge 37 that is adapted to be brought against the teeth of the dieor chaser seated in the pocket in the die-holder 29, as seen in Fig.VII, its movement being limited by a stop 29. This gagearm is rockinglysupported by a rod 38, thatis seated in the die-holder and the lower endof which is adapted to move in a runway 22 in the slide 22. (See Figs.VIII and IX.) The rod 38 is loosely positioned in a sleeve 39, mountedin the die-holder and adjustably held by a set-screw passing through thedieholder and bearing against said sleeve- (See Figs. I, II, and

4:1 is a spring surrounding the rod 38 at its upper end and seatedbetween the head of said rod and the upper end of the sleeve 39. Thisspring serves to support the rod and maintain the gage-arm 36 fixedthereto in any adjusted position corresponding to the seating of the rodsurrounding sleeve 39. It will be seen that by shifting the sleeve 39 toany desired position and securing it through the medium of the set-screw40 the gage-arm will be caused to rest against the lower end of saidsleeve, and therefore be maintained at the proper elevation to bearcentrally against the teeth of the die, according to the positioning ofsaid die in the die-holder.

For the purpose of gaging the setting of the die-holder 29 in order thatthe die or chaser confined therein will be properly presented tothe'grinding-Wheel by which it is to be grou nd I provide upon theperiphery of said die-holder at.29' a scale that is adapted to registerwith a mark upon the slide 22. (See Fig. VI.) In Figs. XI to XIII, I.have shown a die or chaser A of the type ground .in my machine and whichis provided with a cutting-throat B.

In the practical use of my machine the die or chaser to be ground isfirst set into the die-holder 29. The gage-arm 36 is then swung into aposition against the stop 29, and the die or chaser is adjusted to saidgage-arm, after which it is secured by clamping it either at its frontor rear side through the medium of the clamp-screw 31 or clamp-bolt 34,according to whatever the alinement of the tool may be. The gage-arm isvthen swung rearwardly into the position seen in dotted lines,

again tightened to hold said plate rigidly.

The positioning of the oscillating plate is determinedaccording to thedegree of curvature in which the throat of the die or chaser is to beground. After the parts enumerated have been positioned in the mannerstated the operator by manipulating the hand-lever 23 causesreciprocation to be imparted to the slide 22, which lies obliquely tothe peripheral surface of the grinding-wheel, and as a consequence thedie or chaser held in the dieholder is carried obliquely across theperiphery of the grinding-wheel, and the throat of the die or chaser isground exactly to the proper curvature by traversing the grindingwheelperiphery in the oblique movement.

I claim as my invention- 1. In a grinding-machine of the characterdescribed, the combination of a grinding- Wheel, a reciprocally-mounteddie-holder arranged for movement obliquely to the periphery of saidgrinding-wheel, an oscillatory member by which said die-holder issupported, and means supporting said oscillating member and adjustabletoward and away from said grinding-wheel, substantially as set forth.

2. In a grinding-machine of the character described, the combination ofa grindingwheel, a reciprocatory slide rockingly supported adjacent tosaid grinding-wheel, and arranged for movement obliquely to theperiphery of said grinding-wheel and adie-holder carried by said slide,substantially as set forth.

3. In a grinding-machine of the character described, the combination ofa grindingwheel, a reciprocatory carriage-bed provided with an uprightarm, an oscillating member pivoted to said arm, a slide movably fittedto said oscillating member, and adie-holdercarried by said slide,substantially as set forth.

4. In a grinding-machine of the character described. the combination ofadie-holder provided with a die-receiving pocket, and means mounted insaid die-holder for clamping the die by either its front or rear side,substantially as set forth.

5. In a grinding-machine of the character described, the combination ofa die-holder provided with a die-receiving pocket, a-clamp-' boltloosely mounted in said die-holder and having an arm provided with astud entering said pocket, and means for adjusting said clamp-bolt,substantially as set forth.

6. In a grinding-machine of the character described, the combination ofa die-holder provided with a diereceiving pocket, a clampbolt looselymounted in said die-holder and having an arm provided with a studentering said pocket, means for adjusting said clampbolt, and aclamping-screw passing through said die-holder in a direction oppositeto the stud of said clamp-bolt, substantially as set forth.

7. In a grinding-machine of the character described, the combination ofa die-holder provided with a die-receiving pocket, and an adj ustabledie-gage supported in said die-holder; said gage being provided With aknife-edge at its free end, substantially as set forth.

8. In a grinding-machine of the character described the combination of adie-holder provided With a die-receiving pocket, a rod pass ing throughsaid die-holder, a die-gage fixed to said rod, and means for holdingsaid rod in an adjusted position, substantially as set forth.

9. In a grinding-machine of the character described the combination of adie-holder provided With a die-receiving pocket, a rod passing throughsaid die-holder, a die-gage fixed to said rod, and means for holdingsaid rod in an adjusted position; said means consisting of a sleeveseated in said dieholder, and a setscreW for holding said sleeve,substantially as set forth.

10. In a grinding-machine of the character described, the combination ofa die-holder provided With a die-receiving pocket, a rod passing throughsaid die-holder, a die-gage lixed to said rod, and means for holdingsaid rod in an adjusted position; said means consisting of a sleeveseated in said die-holder, a set-screw for holding said sleeve, and aspring surrounding said rod and bearing against said sleeve,substantially as set forth.

EDW AIH) J. MILLER.

In presence of NELLIE V. ALEXANDER, E. S. KNIGHT.

